FreeCAD for 2D drawing

[Roy_043]

How would you translate the '=' constraint to a TD drawing?

[abdullah]

ping

Any thoughts ?

I have a limited knowledge of Technical Drawing. I remember doing technical drawing in high school (with pencil). My teachers did not give me a reference about what should be dimension-ed in them. I was just told not to put dimensions that could be easily derived from others (probably for fear of overconstraining or overdimensioning). Only in "overconstrain" when something was not evident if usable to manufacture (but never actually had manufacturing classes). I do not know if there are actual standards or best practices here.

I rarely use TD, as I 3D-print or CNC-mill as a hobbyist. I have done it a couple of times when I needed to present so blueprints and used 3D objects.

I have just made a sketch and imported the sketch in TD. I see the profile. I see no auto-dimensions. It is easy to dimension with TechDraw. Maybe it was too simplistic. It worked good.

My guess is that TechDraw creates its view out the profile edges/wires of the Sketch, and not from the geometry in Edit mode. I can imagine two solutions. Because I have seen there is a button for Draft objects, it may be possible to do a custom command to add an sketch, which would read the geometry and constraint geometries. Alternatively, I can imagine an add-on that would read geometry and constraints and create a TD object with some dimensions mimicking the constraints.

I tend to think that a professional will create different dimensions than dimensional constraints, because they appear to cover different goals. However, probably it would not harm if a custom command could add the profile together with equivalents of the dimensional constraints.

I admit I did not understand your comment about switching to 3D view. But I do not have the user experience with TD, so most probably I never faced it.

[drmacro]

There are many standards, ANSI, ISO, MIL, DOD to name but a few.

That's the beauty of standards...there are so many to choose from.

[Zolko]

I have just made a sketch and imported the sketch in TD. I see the profile.
...
I admit I did not understand your comment about switching to 3D view.

what I mean is that once you have imported the sketch into TechDraw, and you edit it, you enter the Sketcher WB which shows the sketch in a 3D window, and not in the TechDraw paper view.

So the question could become: would it be difficult to enter the Sketcher WB directly from withnin TechDraw and retain the TechDraw 2D view ? Or, alternatively, would it be possible to create a new TechDraw object that, when invoked, would use the Sketcher's tools and solver but retaining the TechDraw visual ?

The real goal woud be : to be able to use the power and ease-of-use of Sketcher in a pure 2D paper environment, to produce constrained 2D printable scale drawings. A sort-of free AutoCAD light.

[C_h_o_p_i_n]

How would you translate the '=' constraint to a TD drawing?

How do you like to have your "design" decision that something has to be "=" documented?
I might be wrong - but - right now - you can just make a screen-shot of your sketch, put it in a Word document or something else.

Constraints - dimensions, angles ... etc - your thoughts on what was constructed based on .. and why ... ?! should also be "documentable".
It's like comments within source. it enhances the readability of your sketch later after a couple of years ...

Thats why i propose to have a documentation layer in sketcher and an direct way to "printout" (or save) what you see in Sketcher as document, dxf or pdf ... (*)

Regards,
Stefan

(*) an to put notes on that paper, the old fashioned way using a pencil ...

[johnwang]

they can, but they must be drawn in 3D first. I've actually done that: create an App::Part, create a sketch representing an A4 paper on XY plane, and then draw various sketches (on the same XY plane), and then create a TechDraw and import the App::Part (containing all the sketches).

Works, but not very user friendly. And you migh need to check some option for a drawing to import wires, don't remember. Hopefully wondererfan will be back soon to be able to implement that sketches be drawn directly on paper.

Maybe write a program to move Draft entities into that Part sketch.

[abdullah]

So the question could become: would it be difficult to enter the Sketcher WB directly from withnin TechDraw and retain the TechDraw 2D view ?

I do not immediately come with a solution that would preserve separated WB architecture.

Or, alternatively, would it be possible to create a new TechDraw object that, when invoked, would use the Sketcher's tools and solver but retaining the TechDraw visual ?

I do not know AutoCAD light.

What you are suggesting at a first glance might work. You would still need to define the mapping. You could create a TD tool, for example, a Python functionality, that would internally uses a SketchObject. You "interpret" TD edges and dimensions, convert this into geometry and constraints. Get the result which you map back to TD. Still, this would not come without challenges. On the merit, I trust you, it has it. Mine is just a comment from the feasibility point of view.

[yorik]

What could be useful is an "automatic create Draft dimensions from sketch dimensions" tool and maybe another contrary tool.

Really Draft could become like AutoCAD Lt. I don't think there is much missing. The most important part for me would be to have good vector hatching. I'd like to tackle adapting the TD vector hatching code to produce Part shapes at some point, that could be used in Draft.

For the rest, I guess it's more a question of identifying and formatting needed functionality, and making a good, detailed list, for example things like this:

- fillet tool: Mode 1: Select two lines or polylines, click the fillet button: An arc is created, with a given radius, connecting the two selected objects. Both get trimmed to the endpoints of the arc. Mode 2: click the fillet button without selecting anything. A task panel opens, allowing to set radius, and select two lines or polylines. The radius is used next time Mode 1 is used

[jonasb]

The real goal would be: to be able to use the power and ease-of-use of Sketcher in a pure 2D paper environment, to produce constrained 2D printable scale drawings. A sort-of free AutoCAD light.

That would be really cool, indeed! I find myself way to often taking screenshots of a Sketch in edit-mode... (and thus loosing accurate scale and vector graphics/fonts)

[jtm2020hyo]

is possible to add any language different to Python to FreeCAD?

https://github.com/tercoide/GauchoCAD

I think than if maybe is so much work to perfect our 2D drawing, FreeCAD could couple other projects, like gauchoCAD or LibreCAD 3.

if FreeCAD already implemented others, maybe this could be possible.